US 2007/0177876 A1 · Chromatic dispersion monitoring method and chromatic dispersion monitoring apparatus, and optical transmission system

Abstract

A chromatic dispersion monitoring apparatus according to the present invention comprises: a photodetector which photo-electrically converts an optical signal; a low-pass filter which limits a frequency bandwidth of the photo-electrically converted electrical signal to be within a range set according to a modulation format of the optical signal and a bit rate thereof; a DC elimination circuit which eliminates a direct current component of the bandwidth limited electrical signal; and a power detector which detects the power of the bandwidth limited electrical signal to detect the residual dispersion of the optical signal. As a result, it becomes possible to easily realize the chromatic dispersion monitoring apparatus of low cost, which is also capable to be arranged on an in-line.

Claims15

Dependent claims

A chromatic dispersion monitoring method for monitoring the chromatic dispersion of optical signal, comprising:

receiving an optical signal to convert it into an electrical signal and also limiting a frequency bandwidth of said electrical signal to be within a range which is lower than a frequency corresponding to a bit rate of said optical signal and also is higher than a minimum frequency set according to a modulation format of said optical signal and the bit rate thereof;
eliminating a direct current component of said electrical signal;
detecting the power of said electrical signal whose direct current component is eliminated;
and
detecting the residual dispersion of said optical signal based on the detected power.

2 more elements

A chromatic dispersion monitoring apparatus for monitoring the residual dispersion of optical signal, comprising:

a bandwidth limiting section that receives an optical signal to convert it into an electrical signal and also limits a frequency bandwidth of said electrical signal to be within a range which is lower than a frequency corresponding to a bit rate of said optical signal and also is higher than a minimum frequency set according to a modulation format of said optical signal and the bit rate thereof;
a direct current eliminating section that eliminates a direct current component of said electrical signal output from said bandwidth limiting section;
and
a power detecting section that detects the power of said electrical signal output from said direct current eliminating section and detects the residual dispersion of said optical signal based on the detected power.

1 more element

Dependencies are inferred from the claim text.

Chromatic dispersion monitoring method and chromatic dispersion monitoring apparatus, and optical transmission system

Life of this patent

Chromatic dispersion monitoring method and chromatic dispersion monitoring apparatus, and optical transmission system

Life of this patent

Abstract

Claims15